For Loop in C.c

#include <stdio.h>
#include <string.h>
#include <math.h>
#include <stdlib.h>
int odd_even(int a){
    if(a%2==0){
        printf("even\n");
    }else {
        printf("odd\n");
    }
    return 0;
}
int num(int a){
    switch(a){
        case 1:
            printf("one\n");
            break;
        case 2:
            printf("two\n");
            break;
        case 3:
            printf("three\n");
            break;
        case 4:
            printf("four\n");
            break;
        case 5:
            printf("five\n");
            break;
        case 6:
            printf("six\n");
            break;
        case 7:
            printf("seven\n");
            break;
        case 8:
            printf("eight\n");
            break;
        case 9:
            printf("nine\n");
            break;
    }
    return 0;
}

int main() 
{
    int a, b;
    scanf("%d\n%d", &a, &b);
  	for(int x=a;x<=b;x++){
        if(x<10){
            num(x);
        }else {
            odd_even(x);
        }
    }
    return 0;
}